Moment 145: The Alarming Link Between Your GUT & Depression: Tim Spector

00:02What is the microbiome? It's the word we use for the community of gut microbes. These are microscopic bugs in our intestines. And it's a biome because it's like this jungle community. It's lots of different species altogether, thousands of them, that coexist in our lower intestine, our colon. and they it's like we've discovered in the last 10 years a new organ in our bodies if you put them all together they weigh about the same as our brain okay so it's that's mind-boggling really to think about all these bugs which uh individually are tiny putting together they actually you know weigh several pounds so you can either think of them as a microbial garden but increasingly i'm shifting that towards thinking as an incredible pharmacy. So all of them are able to pump out chemicals all the time that are vital for our body. So thousands of different chemicals are pumped out every minute by these gut microbes when they're fed the right foods. And these chemicals are key for our immune system. Most of our immune system is actually in our gut.

01:22Most people don't know that. We think it's under our armpits or somewhere. But actually, all the immune cells are actually talking all the time to our gut microbes through these chemicals. And our immune system obviously is crucial for our whole body and fighting aging and cancer, COVID, infections, allergies, all these kind of things. So then you've also got the microbes can produce chemicals that affect the brain and will make the difference between you being happy or sad or we know that they're vital in depression.

01:58Important for regulating how much you eat, your appetite, when you feel full. They also provide key vitamins for you, all the B vitamins and many other components. It's neurochemicals like serotonin that's key for the happiness and how antidepressants work are all produced by your gut microbes. So we're slowly learning that these guys are absolutely crucial to how our body responds to anything coming into it, whether it's painkillers, whether it's antidepressants, whether it's chemicals in the form of food.

02:33and this is why you know i want people to think about food very differently than we have done in the past the idea the old idea that food is just calories macros you know it's fats and carbs and proteins those four things you know that's 100 years old mentality but key to it is this this core of our gut health which we've ignored totally and this was this big aha moment for me after research for 10 years what why would identical twins twins be different what could it be and it turns out their gut microbes are different that's the only thing I've ever found in 30 years that's really different about identical twins and that explains why one gets cancer the other one doesn't why one gets an autoimmune disease or one's depressed and one's happy so for me that the twins were a perfect um obvious way to show that how important these these microbes are for all of us what are some of the biggest myths you encountered as you started researching the microbiome that most people currently believe that i probably sat here now believe about how to keep my um my gut healthy what are some of those key myths because i know you like myth busting well i think most people believe that probiotics in yogurt get killed by

04:04your stomach acid so they don't work because you're everything gets killed off that's a common one i hear but they don't no some get killed but you're ingesting billions so always enough get through to have an effect and we know that probiotics do work although the best probiotics are in food rather than in capsules and there's plenty of fermented foods which is the same I think most people know very little about microbes I think that most of them are harmful so oh I've you know they they cultured this microbe or they found a parasite 50,000 people have now looked at their gut microbes in the US and the UK. In the UK, 24% have a parasite.

04:53And that parasite is actually beneficial. It's called blastocystis. And it's associated with good health, being thinner, having less internal fat, lower blood pressure. And, you know, in the past, we're trying to kill it off. And actually, the reason we're in this state is we've killed off a lot of our good bugs so i think people need to realize that most of the bugs in our in our system are trying to help us and we've actually lost half of the good ones compared to if you go to hunter gatherers or you know i spent some time with the hadza tribe in africa and you know they have twice the number of species that we have because they don't pop antibiotics they don't have sterile foods they have a very wide range of diverse plants etc so i think people think that you know their gut microbes are really only there to hurt them when they have a bad kebab or something uh they don't think of all the positive benefits they don't think that you need to build them up and that actually you know they're like a the more you've got the better it is how do i build them up how do i become more like that tribe you have to have a more diverse range of plants so we did a study a few years ago with British

06:19and American guts that showed that if you can get up to 30 different types of plant a week you maximize your diversity of species in your gut and that's that diversity that we want remember 30 plants you look a bit shocked but that's um it's a plant is a nut a seed it's not just kale it's a herb it's a spice and things like coffee are a plant to me because it comes from a fermented bean so it's that diversity it's having more fermented foods it's having a range of colors it's cutting out the ultra-processed chemicals as well, which all the groups in the population that have the best gut microbes, they don't eat ultra-processed foods, they don't have antibiotics, they don't have this modern Western lifestyle.

07:20The microbiome as an organ, one of the things you talked about earlier was the impact it has on mood. And, you know, this podcast was started as kind of a business podcast. We have a lot of people that are interested in you know being more productive being more successful reaching for their goals how significant and how pertinent is the microbiome on my performance as an entrepreneur as a business person what do i need to know about the relationship as well it's my mood my performance my mind well we know more about mood than than anything else um and so we do know that depression and anxiety is intricately linked to the quality of your gut microbes.

08:01We know this from mouse studies where they've transplanted poo from anxious mice into sterile mice and those new mice then become anxious and depressed. Really? So it's a transmissible condition. And if you go back to me telling you that one of the chemicals that our microbes produce is serotonin okay some sort of cuddle you know love friendly warm um chemical that affects our brain that you know is the key to dopamine and everything else that goes on in our head so the levels of that are really important for us having the right neurochemical balance in our head that stops us getting very depressed or very anxious so we know that you can transmit it between animals so when they say they take the poo out of one mouse they put it inside its gut inside its stomach to give it the same microbiome makeup inside its stomach yeah so then that mouse will become depressed and anxious yes so a lot of the science behind microbiome is based on large-scale human studies where you've just got um cross-sectional data or this is associated with this but you don't know if it's cause or effect and so there's this whole other group that's been going off of projects for 30 years where they have these sterile mice who have no microbes

09:24and you create in a lab these other microbes that you would make them anxious or they're genetically anxious. You look at their microbes and you take their microbes and you put them into the sterile mice and you can change their mood and their attention span and everything else about that. So that shows that these have a direct effect rather than just being secondary. And that links to the human data that shows if you take groups of depressed or anxious people, virtually all of them will have deranged microbiomes and be producing abnormal chemicals.

10:01And there have been now some recent studies showing that compared to traditional antidepressant medication, probiotics do as well in many of these studies. if you give a course of probiotic medication. But even more impressive is if you give them a Mediterranean gut-friendly diet. You get actually better results with more remission than you do with antidepressant medication. So it's one of the best examples of how feeding your gut can actually improve your mood.

10:38And it's particularly important because we're seeing an epidemic of anxiety and depression. that's partly because of not having many good gut microbes to start with lots of junk food diets which make it worse and of course once you go into that cycle once you're depressed you're not thinking about food the last thing you want to go out and is you know oh i've got to go and get my kimchi today you know you just what it's just fuel so once you once you understand that you realize if you want to help someone with depression you know the first thing is not to put them straight onto an antidepressant which in many cases doesn't work because of this individuality as we're talking about which probably again related to the microbes because they break down the tablet into its active chemicals but is to make sure they've actually got gut-friendly diet and so this is a really exciting area of research